python基于Tkinter库实现简单文本编辑器实例

## {{{ http://code.activestate.com/recipes/578568/ (r1)
from Tkinter import * 
from tkSimpleDialog import askstring
from tkFileDialog  import asksaveasfilename
from tkMessageBox import askokcancel     
class Quitter(Frame):            
  def __init__(self, parent=None):     
    Frame.__init__(self, parent)
    self.pack()
    widget = Button(self, text='Quit', command=self.quit)
    widget.pack(expand=YES, fill=BOTH, side=LEFT)
  def quit(self):
    ans = askokcancel('Verify exit', "Really quit?")
    if ans: Frame.quit(self)
class ScrolledText(Frame):
  def __init__(self, parent=None, text='', file=None):
    Frame.__init__(self, parent)
    self.pack(expand=YES, fill=BOTH)        
    self.makewidgets()
    self.settext(text, file)
  def makewidgets(self):
    sbar = Scrollbar(self)
    text = Text(self, relief=SUNKEN)
    sbar.config(command=text.yview)         
    text.config(yscrollcommand=sbar.set)      
    sbar.pack(side=RIGHT, fill=Y)          
    text.pack(side=LEFT, expand=YES, fill=BOTH)   
    self.text = text
  def settext(self, text='', file=None):
    if file: 
      text = open(file, 'r').read()
    self.text.delete('1.0', END)          
    self.text.insert('1.0', text)         
    self.text.mark_set(INSERT, '1.0')       
    self.text.focus()                
  def gettext(self):                
    return self.text.get('1.0', END+'-1c')     
class SimpleEditor(ScrolledText):            
  def __init__(self, parent=None, file=None): 
    frm = Frame(parent)
    frm.pack(fill=X)
    Button(frm, text='Save', command=self.onSave).pack(side=LEFT)
    Button(frm, text='Cut',  command=self.onCut).pack(side=LEFT)
    Button(frm, text='Paste', command=self.onPaste).pack(side=LEFT)
    Button(frm, text='Find', command=self.onFind).pack(side=LEFT)
    Quitter(frm).pack(side=LEFT)
    ScrolledText.__init__(self, parent, file=file) 
    self.text.config(font=('courier', 9, 'normal'))
  def onSave(self):
    filename = asksaveasfilename()
    if filename:
      alltext = self.gettext()           
      open(filename, 'w').write(alltext)     
  def onCut(self):
    text = self.text.get(SEL_FIRST, SEL_LAST)    
    self.text.delete(SEL_FIRST, SEL_LAST)      
    self.clipboard_clear()       
    self.clipboard_append(text)
  def onPaste(self):                  
    try:
      text = self.selection_get(selection='CLIPBOARD')
      self.text.insert(INSERT, text)
    except TclError:
      pass                   
  def onFind(self):
    target = askstring('SimpleEditor', 'Search String?')
    if target:
      where = self.text.search(target, INSERT, END) 
      if where:                  
        print where
        pastit = where + ('+%dc' % len(target))  
        #self.text.tag_remove(SEL, '1.0', END)   
        self.text.tag_add(SEL, where, pastit)   
        self.text.mark_set(INSERT, pastit)     
        self.text.see(INSERT)          
        self.text.focus()            
if __name__ == '__main__':
  try:
    SimpleEditor(file=sys.argv[1]).mainloop()  
  except IndexError:
    SimpleEditor().mainloop()